In Hanover, MI (in the vicinity of Jackson, MI) about 10 years ago
I visited a collection of restored reed organs housed in an old WPA-era
school building.  The restorations are all by one individual and not
every one is faithful to the original state of the instrument.
(Occasionally he fabricated cases, etc., from whatever he had handy.)

I am sorry that I do not remember the name of the restorer or of the
museum, but I recall it being open once every week or once every two
weeks (Saturday or Sunday) to the public.  Obviously you would need
more detailed information to get there, so perhaps someone else knows
of this collection and contact information?

Good luck,
Steve Sorenson